Skinning machine



Feb. s, 1949@ F. J. com. f 2,461,466

SKINNING MACHINE Filed July 18, 1944'A s sheeis-shet 1f ull-num y g nllluum INVENTQR ATTORNEY Frederik MJ @odd I F. .n.fsoADv 2,461,466

SKINNING MACHIE Feb. 8, 1949.

3 Sheets-Sheet 2 Filed'uiy 18, .1944

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' INVENToR -vBY l( v v f ATTORNEY Y Feb. 8,' 1949; F. .1. 'coAD-v SK'INNING, MACHNE Filed July 18, 1944 5 sheQts-shvet a INVENTOR ATTORNEY Patented Feb. s, 194e deceased, assigner, by mesu@ assignments, ,.tv

..&- Comiis-nn Chicago, .111-, a rcrrelzatitil .ef Illinois Application July -18, 1944, Serial No. .545,.4'7

5 Claims.

This invention relates to a mach-ine .for remov-v ing skin from meat cuts and more particularly to a ldevice for forcibly pulling skin from a. meat shoulderor ham cut.

It is an object `of this invention to provide a machine for pulling skin from a meat cut.

It is another object Lof this `invention to provide an improved means for removing skin from a plurality of shoulder cuts or .ham cuts.

Gther objects Will appear below.

In preparing certain meat items for the ,consumer trade it is necessary that the `skin ,be removed from the cut and particularly yis this v true when ham and shoulder cuts are prepared for the retail Ytrade with-the bone removed. Furthercannot be utilized it is removed from these cuts i for its value as a lay-product.

It has been the practice in the .past to remove .the skins by a cutting `operation ,and mechanical cuttingv means are available to remove the skin from a fiat slab of meat. ever, an irregularlysljiaped eut such asia shoulder or ham cut is kto ee skinned, it is .necessary that a hand cutting operation be performed to effect a separation of the skin.

In removing the skin from an irregularly shaped cut yby hand, not only is considerable labor involved .but also the labor ,must he quite skilled. If the skin is to vbe used in the `preparation of leather, it must be removed in an undamaged condition and `yet-it is desirabletoseparate the skin from the cut without leaving any meat or fat clinging to the esh side .of theskin. It is seen therefore that the most efficient Aremoval of the skin requires the operator to yrapidly sever the skin from the meat cut by slicingrk through the layer beneath the skin. It is thus readily apparent that considerable `loractice is required before an operator v can perform Vthis relatively delicate `operation in a rapid manner.

The present invention has been provided Ato make available a Skinning machine adapted to the removal of skin from an Airregularly shaped When, .hovvcut of meat without necessitating a cutting op ing the skin.

'lamb cuts.

fren-T ewipe man 1 1 'es .e .i

'.lhe machine terrines an l@mbestefait .0f :the subjectpf lthis invention `is shown Yin the drawings wherein:

.Risers .l represents e side elevation partly brok-en away Aof the preferred form of .the inacliine for simultaneously .handling a ,plurality .Qf .irregularly shared .cutsdur-ine the siriani-ns ,0,10-

, eration,

.Fissi-'e .2 represents an rad elevation partly .broken sway of the .preferred .ferm .of .ms- Qhtlefshown in Figure .1,

Figure `3 represents plan -vievv partly breken away of ,the preferred folmoi the :machine ShQWn in Figure ;l

Figure 4 represents a side elevation o fa second iormoi the machine,

Figure ,5 is a 1plan .view ,of .the .machine shown in .Figure A,

Figure 6 is a perspective view of a bifurcated ghook ,element .shown .in `lligures 4 and 5 ,f or' en- :gagingthe .meatc1112.`

I n general, the Vpreparati-on .of boned shoulder and Aham .Cuts includes@ stimme' sperati@- While the Vpresent .invention finds' `particular ap-- fullest-t0n to the Skinning 0f such portions ,oils carcass, ut will .be apparent ,as the .description proeeeds .that the ,invention may 11nd use inthe skin/ning of `larger cuts .and up .te .one-,half and Whole carcasses. These ,ham and shoulder cuts, however, have e. generally irregular shape vand thus .cannot readily Lbe kadapted y to v a v rriachine cutting operation for removal of the skin `f roin around the entire vperiphery .of the cut. The .herein ldisclossl .invention .is .therefore particularly adapted tothe skinningof cutsof this type by .a skin pulling method. When .the .shoulder Land ham cuts are removed freni ,the `carass the shoulderucut, :f or example, is ,s vsled `so that the huinerus bone extends `longitudinally through the cut. The .ham is ,removed ,in sucha manner vthat .the femur Ebone extends .thlsush .the @at Each of the ,huinerus and @murbones of course isiorined with an enlarged end Whorel thebones engage the shoulder and elbowjoints orhip and knee joints respectively.

It has ,beenfound that the skin maybe rapidly V i,engiovel froinsuch an irregularly shaped cut'j'by apulling action. When .the skin is'properly preparedand is forcibly ldrawn from the cut, the

fell layer separates and the skin `is stripped o without damage to the Irn'eat `or itself and itwis generally free of all lclinging; meat Aandv fat particles. 'This yis true withrespectto beeand With pork', however, which xhas ino 55 layer of Afell vbetween the skin and Lthe -iiesh,itlie skin is similarly peeled off when pulled in this manner.

To remove skins by pulling, in accordance with this teaching, the cut is fixed in a machine designed for a power pulling action whereupon the skin is pulled back upon itself so that it is peeled from the meat. The shoulder or ham cut is prepared for Skinning by having a tab of skin lifted up on the outside of the leg cut so that it may be engaged by suitable clamping means and, in addition, the skin is just cut through along a line generally parallel with the longitudinally extending bone of the cut on the inside portion of the leg of the animal. The inside out is carefully made so that only the skin is cut. The incision need be no deeper.

When pulling the skin from the cut it has been found that the most satisfactory skin removal results from engaging the skin in a manner such that it is ripped from the cut by reversing the skin upon itself. The fell layer of beef or lamb, for example, is more quickly broken by this procedure because the pulling force is always directly applied to the fell at the fold as the skin folds Vover upon itself. The fell is comprised of many small fibers interlaced and bonded to the skin and flesh. This manner of pulling exerts a maximum pull against a fewer number of fell fibers than any other method so that the fibers are tensioned and broken before the pulling force can be substantially transmitted and distributed through the flesh or other more remote fell bers. A similar advantage in directing the application of the pulling force substantially to the line of separation at the fold of the skin is also realized in Skinning pork, and the pork skin is easily rolled back upon itself in a manner to be quickly and easily separated from the flesh and fat.

A machine adapted to perform this invention is shown in the drawings and referring to Figure 1, ham cut IB is shown in position to be engaged by a clamping means to eiect a removal of the skin from the cut. The ham` has femur bone I I extending therethrough and a skin tab denoted I2.v The femur bone I I has an enlarged hip joint end I3 at the butt end of the out, which may be engaged between one f the pairs of the prongs I4 and I5 forming a holding means for a cuton ,y

the Skinning machine.

The two pairs of prongs I4 and I5 are fixedly mounted on a suitable movable supporting head I6 slidable in the direction of the arrows shown in Figure 2. The head I 6 may be mounted upon guide tracks I'I and I8 for this lateral movement across the machine for a purpose that will appear more fully below, and the two pairs of prongs are supported on the head to hold the meat cut engaged thereby on table I9. Suitable stiffening arms I6' may be fixedly mounted on the side of supporting head I6 which faces the frame of the machine, the arms carrying rollers at their free ends to bear against the frame of the machine in order to brace the hooks against the frame of the machine when the skin pulling force is applied. 1t is to be understood of course that the skin may be slit on the inside of the leg when the tab is loosened on the outside before the cut is placed on the table and between the prongs.

` When the ham is so positioned on the table I9 and the end I3 of the bone is firmly engaged between the one pair of prongs I4 and I5, a clamp 2is fixed tothe tab I2` by engagement. of

4 jaws 2| and 22 whereupon the clamp 20 may then be connected to a driven pulling mechanism.

Clamp 20 may take the form of a pincher like device wherein the jaws 2l and 22 are driven together upon closing of arms 23 and 24. Arms 23 and 24 are normally urged apart by spring 25 and are closed together when links 26 and 2 are pulled outwardly as when chain 28 is connected to the pulling means. This construction provides a clamping device which is normally urged to p0- sition for releasing anything engaged between the jaws 2l and 22 yet when once engaged, and as long as pulling action is exerted, the jaws tend to engage the skin more tightly as the pulling effort increases. As long as the closing tendency caused by the pulling a-ction is greater than the contracting force of spring 25, the skin will remain ,firmly engaged between jaws 2I and 22, and the spring tension is selected to be such that the jaws remain closed until the skin pulling operation is complete.

The flexible link or chain 28 for transmitting the pulling force to the clamp 20 is xed at one end to a carriage 30. Carriage 30 is provided with a downwardly extending hook arm 3l adapted for engagement with the driven pulling means. Carriage 30 is designed to slide or ride across the top surface of the pulling machine and has suitable bearing members 32 and 33 for supporting the carriage on this surface or slideway. A slot 34, Figure 3, in the surface permits the hook arm 3| to extend downwardly therefrom for engagement with the pulling means.

The invention here shown makes use of a pulling means taking the form of a pair of driven chains 4U and 4I carried on suitable sprocket wheels. These two chains are interconnected at spaced points with cross bars 42 and the upper run of the composite chain structure is positioned below slot 34 to cooperate with the hook arm 3I to drive the carriage forwardly in the direction of the arrow as shown in Figures 1 and 3. The chains 4i! and 4I may be driven from any suitable power source to effect the desired pulling action.

The above described mechanism is operative to engage the skin of any cut fixedly held with respect to chains 40 and 4I so that the skin may be pulled therefrom. A cut may be laid on the table I9 and engaged in the machine by forcing the bone between one of the pairs of prongs I4 and I5, as shown in Figure l. The head I5 is then adjusted laterally to place the cut generally in front of the slot 34 whereupon the jaws 2| and 22 may be closed onto the tab I2 and the chain 28 pulled to clamp the jaws. Then the hook arm SI is dropped down through slot 34 and between chains 4) and 4I for engagement with one of the cross bars 42 of the driven pulling means. When the hook arm is taken up behind one of the cross bars 42, it is carried forwardly and carriage 30 rides forwardly on the slideway .on the upper surface of the frame of the machine. The iorward motion oi the carriage 3U through link 2S and clamp 2li pulls the skin 01T of the out progressively from one end to the other by reversing the skin upon itself. The jaws 2I and 22 are, by

this action, driven together so that the skin is firmly engaged during the entire pulling operation. l A

It has been found that when the skin is pulled from a meat cut in this manner the skin is removed quite satisfactorily without damage to the meat structure itself orto the skin. 4As soonas the skin is completely removed from `the out, the

:pulling force :against .chain vZllis released and ehe clamp .20 fis opened :by spring 25 so 'that the skin `may ibe released. .As .soon :as the .skin has been .pulled from the -.:cut, the .carriage 330 reaches ap :proximately the .end of the track and the clamp and carriage may be Ylifted 'from the lmachine and returned tto the starting point for .attachment to a subsequent cutfor Skinning.

While .one rout iis in position :and during the skin `pulling .operation being 'performed thereon inthe machine .shown `in 'Figure l, `a second cut may be :engaged on the other pair of prongs fill and :i 5. The tab :i 2 zof `:this second cut may then be raised and engaged onto a clamp i218 so that as soon as the skin pulling process being performed,

I:is completed, the head i5 maybe shifted .to move .the .skinned cut Aout oi position and `place the second cut before slot 3Q so that hook .arm 231i or `the clamping structure yfixed `to its skin, may vbe dropped into Vthe .pulling means. head mounting means i5 for the pairs of prongs M .and t5 makes it `pos-sible for yone operator to utilize the machine to the fullest possible extent.

A modified form of 'machine is shown in -Figure 4 and iin this device a birfurcated hook 5E! as shown in Figure 6, is provided, having diverging arms for rengaging the bone :of the meat lout and a clamp 5l is also provided for xing tothe skin. The jaws 52 and 5S of the .clamp are urged together by manipulation of arms edv and 55 which in turn are so connected that when a pulling action `is exerted against the clamp, the jaws are driven together. The arms `5 and 55 are interconnected by a link 55 vwhich at one end, is pivotally connected to the arm 55 and vat the other end, `is slidably connected to arm 54 in a suitable slot. The sliding end of link 55 is connected to the chain El any pull exerted on the link 5G by chain 51 causes the lower end of 'link 5'6 to slide to the left, as in Figure 4, so that arm 55 is pulled downwardly .to drive the Ajaw 53 .against jaw 52.

The .clamp is ,slidably mounted .in a movable carriage 6i) carried upon the top frame of the machine in suitable slide ways.. the clamp being slidable in the carriage Aon a guide way 5i.. The carriage is adapted to -be driven by -a suitable power means vsuch yas the air motor lil and the driven piston of the air motor is connected to the carriage through .the connecting rod il, which is xedly connected to carriage 6B.

In the operation of the mechanism shown in Figures 4 and 5, the clamp 5i is attached to the skin tab l2 and ythen the power is supplied to the air motor so that the piston is driven to the left as shown in Figure 4. When the connecting rod .'H moves to .the left, the carriage G0 is carried therewith. The clamp 5I remains stationary until the slack in .the chain 5l is taken up'where- -upon continued movement of the carriage causes the jaws 52 and 53 to be engaged tightly on the skin flap so that further movement of the carriage causes a drawing action to be applied against the skin so that it is forcibly stripped from the meat cut engaged upon the hook 50.

The motive power to the motor 10 is controlled by a suitable air valve 12 located adjacent the working station of the machine and by suitable manipulation of the valve the piston and the air motor can be driven to the left or right to eiect rst a pulling 01T of the skin and thereafterv The movable i the above described As above stated, the fskin=of11a shoulder 'for haml cut iis :prepared for removal by ireeing fa. "tab yfof skin adjacent the outside fof alie-shoulder v:or hip joint. The surfacefon the 'inside of'ihe :animals leg i-s A:cuit fskin `deep along fa "line substantially parallel lto the -ffemur or humerus 'bone disposed in the cut. When 'the skin iis prepared Qin this manner., @the iskin may be forcibly pulled fon of the out y:without damage to the lskin or the meat vcut.

:shown lin Figure l1 the :out y:can be laid Lover the Stable with 5the `skin -tab on top ofthe ercut Y'so that the jclamp may be `engaged on the tab and the skin pulled iback 4.upon `itself as itherclamp `moves -overithe #top idf 'the `cut. "-In some instances, 2the cut can be more easily placed -on the hooks if ithe fcut vlis handled :as ishown iin Figure el. Tn this fins't'ance, .the out 'iis merely vplaced on ithe hook 50 4in suc-h Aa -manner that ithe :shin ita'b ll2 iis :adjacent 4the clamp and when fthe clamp -is fined to the yitalo the out iis allowed 'to 1tall @over ontofthe clamp Lso that the enlarged l:end o'f the .bone rlis engaged vin l.the hook las the cut -ialls fonte the clam-p. Thereafter, as lthe clamp is fdriven out Yfrom '-under ithe fcut, theekin is forcibly fdrawnsoff lfof the \meat. The -manner of 4engaging-the meat out onthe hooks as `shown in either Figures illand Ji `may ibe I-used Vinterchangeably with either iform ofthe machine.

v"Ihe above description of Jthe machine shows its' application -to cut-s ioi irregular lshape. It 'is 'obvious that fa ilat cut could '-be iinedly engaged and xits skfin attached to Ione -of ithefclamping Imeans so that the skin could be 'drawn ifrom the cut as described above. The machine iis #particularly adapted, however, to T'the removal of skin Yfrom lirregular cuts Isuch as shoulder 4and 'ham `cuts where vthe meat maybe separated from the skin by 'a mere pulling action.

Intri-mming certain cuts for 4'the retail trade, it is the rcustom `to leave a ring of skin around 'the AVhock or yshank end Iof the cut. This may s'be 1ac" complished in the present ymachine by cutting through Vthe skin lat the Ahook 'end vbefore pu'lling Vthe skin from the meat cut. It is likewise 'apparent that theskin maybe stripped fromthe cut :by pulling it from the 'hook end toward the butt end.' The preferredv stripping, however, is as above described.

Many modifications of the invention disclosed herein may .occur 'to those :skilled in the art. While the invention `has been described .and il- 'lus'trated Wi'thmeans for .Tholding the cu't stationary while pulling the skin, .'it is readily apparent that .the vskin could be xed and thecut moved. A single or plural grouping Yoi? pulling .means .may be associated with clamping means to hold the nuts, 'but as shown in the preferred form vof .the .machine .as shown in .Figures .1 and .2, a single pulling means is adapted to cooperate with a plurality of holding means. All such modifications are considered to be within the scope of the following claims.

I claim: f

1. A machine for pulling skin from a, meat cut surrounding a bone having enlarged ends such as the humerus bone of a shoulder cut and the femur bone of a ham cut, comprising means to engage the bone of said cut at one of the enlarged ends of the bone, a clamping means adapted to beflxedly secured to the skin, pneumatically driven means to pull the clamping means away from;

fsaid ?engaging means rin a iadirectionitc spilli-fthe skin from' the cutv progressively from one end-to thej otheryand meansV to .connect theipneumatically driven means'to. the olampingmeans;

22.A-vmaohine for pulling skin fromfa meat out Y surrounding a bone `having enlarged ends such'as Athehumerus bone of a shoulder'cut-and the -femury bonev cina ham cut comprising means to engagethe bone 'of said-1cutat fonefo the; enlargedends voi' the vbone,4 kaclampinggmea-ns :adapted to be lxedlylsecuredyto-theskin, and power driven endless chain means adaptedi-for .connection with the clamping means -to pullthe clamping meansy away `from said engagingmeans a direction to pull the skin Vfrom the cutj-progressivelyfromfoneend to the-others:y is i ..1' -3.A machine forpulling skin `iromv'aneat -cut `surrounding a bonehaving Venlargednds such as Ythe VVhumerusibone of a shoulderfcut'gand the femur :bone of a ham cut, comprising ajplurality .-of; means such individually adapted toiengagethe bone-'of one of said cuts, all ofsaid engaging means being mounted on movable supporting means, means including a Vclamp'adapted-to be -xedly secured to the s kin of a out, andfasingle -1 gaging means in a direction to pull theskin from fthecut there engaged progressively from one end totheother. Y 4 Y u', f d 4. A machine for pulling skin froma-rneatcut surrounding a bone having enlargedends V,such

as the humerus bone of a shoulder cut andthe femur bone of a haml out, said niachinejbeing :built upon a suitable frame; comprising aplurality of means each adapted to individuallyengage the bone of one of said cuts atonevohivthe enlarged ends of the bone;n said'engaging Ameans each being xed to a supporting vmeans ymovable laterally across the frame of the machinema clamping means adapted to be xedlysecured'to the skin of a cut; said clamping meansfi'nclding a exible link and a Vcarriage connected'tdtlie end of the link; a slideway on the upper portion ,of the frame of the machine on whh said'ca- `ria`ge is adapted to'slide; said s lideway having a slot therein 'extending longitudinally dif'saidnal,chine frame; a driven means disposedbelowjsaid s lot; means rextending downwardly from said'carriage and adapted to pass throughthe slot to be engaged by said driven means; meanson'said driven means for cooperating with said downwardly extending engaging means; said driven means being effective, when interconnected with said carriage through the `engaging meansto drive the carriage" along the' 'slidewayfe and the supporting means for said bone engaging means being movable laterally across the machine to position a cut engaged thereby in proximity to one end of said slot so that when the carriage is driven along the slideway, the clamping means will pull the skin from the cut progressively from one end of the cut to the other.

` 5. A machine for pulling skin from a meat out surrounding a bone such as the humerus bone of a shoulder out and the femur bone of a ham cut; comprising a pulling means to forcibly draw the skin from the cut; and a holding means to relatively xedly engage the bone of said cut; said holding means being adapted to be solidly supported in a position to cooperate with the pulling means; said holding means including a biiurcated means having diveiging arms to engage the bone behind the enlarged end thereof as the skinis being pulled from the out positioned in the holding means; and said pulling means having a clamping means adapted to be iixediy secured to the skin adjacent the holding means; and said pulling means also including a power drive to pull the clampingv means away from the holding means to progressively pull the skin from the cut. Y

6. A machine for pulling skin from a meat cut surrounding a bone such asthe humerus bone oi a shoulder cut and the femur bone of a ham out; comprising a pulling means to forcibly draw the skin from the cut; and a holding means to relatively ixedly engage the bone of said cut; said holding means being adapted to be solidly supported in a position to cooperate with the pulling means; said holding means including a bifurcated means having diverging arms to engage tlie bone behind the enlarged end thereof as the skin is being pulled from the cut positioned in the holding means; said pulling means having a 'clamping means adapted to be xedly secured to the skin; said holding means and said clamping means being so positioned with respect to each other that said clanuoingV means pulls the skin from underneath the out while reversing the skin upon itself; and said pulling means also including a power drive to pull the clamping means away from the holding means to progressively pull the skin from the cut.

FREDERIC J. COAD.

REFERENCES CITED rEhe following references are of record in the iile of this patent:

UNITED STATES PATENTS Piperv Nov. 4, 194:1 

